PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 75 



therefore limited to the middle eastern seaboard States so far as 

 is known at present, while H. texensis is so far known only from 

 eastern Texas. 



Hasstilesia texensis differs in a number of respects from H. tricolor 

 and is undoubtedly specifically distinct. The principal and most 

 striking differences are in the size of the suckers and in the formation 



c.tr. <- 



Figures 1-4.— l, Hasstilesia texensis. X83. 2, Cross section of same through trans- 

 verse PORTION of intestinal CECA. X166. 3, CROSS SECTION OF SAME THROUGH POS- 

 TERIOR PART OF ACETABULUM AND ANTERIOR PORTION OF CIRRUS POUCH. X166. 4, CROSS 

 SECTION OF SAME JUST ANTERIOR TO GENITAL OPENINGS AT LEVEL OF LaURER's CANAL. 

 X166. 



Abbreviations: ac, acetabulum; a. t., anterior testis; c, intestinal cecum; dr., cir- 

 rus; c. p., cirrus pouch; c. tr., transverse portion of intestinal ceca; L. c, Laurer's 

 canal; met., metraterm; o. «., oral sucker; ov., ovary; ph., pharynx; p. g., prostate 

 glands; p. t., posterior testis; sh. gl., shell gland; ut., uterus; vH., vitellaria; y. d., 



YOLK DUCT. 



of the uterus in adult specimens. Stiles and Hassall give the diam- 

 eter of the oral sucker as 88ju to 112ju; in two specimens kindly loaned 

 from the United States National Museum Helminthological Collec- 

 tions the sucker measures 93/i and 87m transversely and 69m and 74m 

 in length, respectively. The specimens have a total length of 710m 

 and 745m and a breadth of 565m. Id specimens of H. texensis of 



